Degenerate Fermi gas of ^6Li
Abstract
The experimental realization of Bose-Einstein condensation (BEC) in ultracold alkali gases has spurred interest in a degenerate Fermi gas. We report our progress on an experiment designed to create a degenerate gas of fermionic ^6Li. The experiment is based upon our successful demonstration of BEC with ^7Li. However, unlike bosons, a gas of identical fermions cannot be directly evaporatively cooled since the symmetry prevents s-wave collisions. One method to circumvent this involves sympathetically cooling the fermions with an evaporatively cooled bosonic species, which in our experiment is ^7Li. Because the triplet s-wave scattering length of ^6Li has an unusually large, attractive value of -2160 Bohr, theory shows that a degenerate mixture of two spin states in ^6Li can undergo a BCS-type phase transition at experimentally accessible conditions.( M. Houbiers et al.), Phys. Rev. A 56, 4864 (1997). Triplet s-wave pairing is accomplished by creating a mixture of two nuclear spin states in an electronically polarized gas. The physical signatures of both the Fermi gas as well as the superfluid phase will be discussed.
- Publication:
-
APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 1998
- Bibcode:
- 1998APS..DMP..LP57M